Since solar panel devices do not generate carbon dioxide while they generate electricity, they are currently receiving much attention as devices that serve to prevent global warming.
There is a type of prior art solar panel apparatus in which a utility interconnection inverter device converts DC power generated by a solar panel into AC power, and then feeds in this AC power to a utility system power supply (for example, refer to Patent Reference #1).    Patent Document #1: Japanese Laid-Open Patent Publication 2005-204485.